Posts Tagged ‘energy efficient’

DIY: Home Energy Audit- The Mechanical System

Thursday, July 14th, 2011

You are getting through the building as a system and now you need to know how the actual brains work.

We’ve gotten through the tools you need, the safety equipment and common sense and how to prepare yourself. Then we discussed the actual building as a system. Now we’re moving on to the actual mechanical systems or what some people call the brains of the house. This would be the heating, cooling and water systems of your home.

Heating System Types

Central- In a central system, air or water is heated in one area and then distributed throughout the system by a fan or pump which is typically controlled by one central thermostat. You check these systems for issues by taking a look at the main system’s records to see when it was last serviced. Check the filters to make sure they are clean and installed properly.

Zone- In a zoned system each room or zone is a self contained system which typically has its own thermostat that controls that zone. You check these types of systems by looking at the baseboards for dust and for potential air leaks in the systems coming from the floor or wall near the baseboards.

Cooling System Types

Space Cooling- is cooling a home by planting trees to shade a home or installing overhangs in the proper way as to allow sun in yet block sun when it is not needed.  Window shades can also be used to block the sunlight and shade your home for thermal blocking. Air conditioning is not always needed, but ducting is typically run through attics and non-conditioned spaces which get really hot. By making sure that ducts are sealed properly ( use of mastic instead of tape so that conditioned air is not leaking straight out into non-conditioned space) you can save money). Another solution to space cooling is to condition an attic an properly air seal an attic and know where you want to create your thermal envelope. Remember your house as a system- take another look at the diagram above and look at all of the paces that air can leak out! Check all of the ducting to make sure that you can’t see daylight through the mastic. If you really want to try to use your incense here you can waft it into you ducts and see if you see any of the smoke coming out through holes; if you see smoke coming out through holes in your ducts, then you can see where the ducts need to have more mastic applied, as that is where your conditioned air is leaking out.

Water System- Hot water is needed to bath and wash dishes and clothes. The temperature of your hot water heater should be set to 120 degrees Fahrenheit. Many people are looking to solar hot water heater systems as they can get up to 70% of their water heated by the sun! This is a fantastic way to save money and see an immediate payback for a home energy improvement. When you are inspecting your hot water system you will want to check to make sure your first two feet of pipe are insulated. Put your hand on the shell of your hot water heater; if it feels warm, it needs a blanket- these can be purchased at big box stores.

Terms to know when looking at mechanical systems in your home:

SEER- Seasonal Energy Efficiency Ratio is the standard for air conditioning efficiency. It is the ratio of the cooling capacity to the power input. The higher the number the more cooling is achieved for each watt of electricity.

HSPF- Heating Season Performance Factor is the most important measure for heatpumps. Heat pumps also have a SEER for their air conditioning function.

EF-Energy Factor is the measure for the overall efficiency of water heaters. It includes the pilot light and standby loss from a tank. Standard gas hot water tanks have been about EF .58 – or about 58% efficient. High efficiency gas tanks above .62 EF and electric tanks above .93 EF qualify for utility rebates. Tankless water heaters range from .79 – .86 EF, while some condensing boilers and water tanks reach above .90 EF.

GPM- Gallons Per Minute is the water flow rate for faucet aerators and shower-heads. Shower-heads are available that work well at 1.6 GPM and aerators that work well at 0.8 GPM.

This is getting exciting, isn’t it?! You’re well on your way on getting through your own energy audit! Next you will find out how to go through your own attic. Why do we have attics anyways? If you have a friend who needs to get started on their own audit, too, send them to the very beginning, and get them started! It is never too late.  If you ever have any questions, or want for us to come do some diagnostics, drop us an email or find us on Facebook!

Nauck Community gets a Green Voice

Wednesday, January 12th, 2011

Bonstra Haresign’s New Construction, The Macedonian Building on Shirlington Road, brings a deeper sense of Community and a new shade of green to Nauck in Arlington.

Situated in the thick of things, the new construction just in front of the Macedonia Baptist Church on Shirlington Road will bring a deeper sense of connectedness and community to the Village of Nauck. Architect Matthew Corell of Bonstra Haresign answered a strong call for a building that could enable low income families to live in homes that are “environmentally and community responsible”.

Part of Bonstra Haresign’s mantra is that they are “rooted in community values and collaboration [Bonstra Haresign is] a full service architecture firm committed to design excellence and client service.” They saw this community in need, and set out to achieve a building that is not only EarthCraft Certified, but also a community incubator program. Corell mentions that this 35 unit building of one and two bedroom homes isn’t just a pretty new face on the Nauck Village Center map, “The Macedonian and it’s big sister The Shelton (across the street) are the first two buildings to be developed according to the Nauck Village Action Plan and act as a gateway from the low-residential single family homes to the north and the soon-to-be density to the south and on down to the more developed Shirlington area.”  Corell and his team utilized the difficulties of the Nauck Village Action Plan (the planning and zoning for the community) to their advantage- creating a sleek, yet modest profile with some rather interesting, thoughtful touches. Note that this building is going through the rigorous EarthCraft Virginia testing to verify that the property is being built to health living standards.

From bottom to top, The Macedonian is something special for the Nauck Community. This 5 story building looks like a four story building from some angles, this is part of the zoning that provided Corell the opportunity to create something a little bit different with this building. In the first level of the building, you will find offices and “incubator” rooms for community members who are seeking to begin their own small businesses; this incubator area gives them a head start with office space to commence working on excelling. The one and two bedroom floorplans are available to families who meet specific income requirements to that they can live in a building which has been constructed to high energy efficiency and green building standards. The slight step in the building where it becomes a 4-5 story building, is an open air roof-top green space: an intricate system of sedum and other succulents called a living roof. Corell recalls this living roof would “add a center piece for the tenants and a private outdoor space that they could enjoy year round. The green roof, by LiveRoof, also has huge environmental impacts: diverting water from the local sewer system, reducing the heat gain of the building and providing an additional layer of insulation…  The upper roof is also energy efficient and is called a “cool roof” due to its high albedo rating.  It has minimal mechanical condensers and fans. ” The living roof is just one way that his team brought a beautiful and effective way to bring energy efficiency and performance to the project.

The standards that the Bozuto Construction company took in creating the Bonstra Haresign design has been that of advanced framing techniques, high performance energy efficient  insulation strategy and healthy indoor air systems through proper air sealing techniques and the utilization of a fresh air intake system for the whole property. The HVAC system is a topic that the whole design and construction team struggled with; Corell wanted a product that would allow for the fresh air intake system but would not be the typical “farm” of HVAC units on the rooftop. One of their engineers suggested the Mitsubishi unit, that they ultimately opted for after much discussion with the HVAC subcontractors who were not familiar with this type of ducted fresh air intake system. The Mitsubishi unit that they purchased is a product that is often utilized in commercial buildings, but is quite widely used in Japanese construction of all sorts. One of the many bonuses of this system is that it will “provided ducted fresh air to each unit.” On the energy efficiency front, this system “will send it’s cooling refrigerant to the condensers in the garage which will then convert this and send it to the west side. So instead of converting 100 degree air to 70, the Mitsubishi takes the 74 degree refrigerant and converts it to 70;” thereby reducing the conditioning needs since air will be constantly tempered. Something that, again, sets this building apart is the light colored roof designed to reflect light and keep the building cooler in the summer and warmer in the winter, as Corell referenced before regarding the “high albedo”.

Not only is The Macedonian project an energy-efficient, low income, multi-family project in Arlington, but it is also a community development project. It’s prime location with close proximity to 395 access, a number of ART buses and even the main S. Glebe thoroughfare, The Macedonian is a great place to kick this historic community back into high gear for its inhabitants. The incorporation of a project such as this within walking distance to the historic Drew Model School, walking distance to the Nauck Town Center and even a gentle stroll to the Village of Shirlington shops, and restaurants-  is bringing new life and new opportunity to this section of the Nauck Community.